The only time I ever put a player in the wrong position is when I have to sub during a game because of injury.

In the short term, playing someone out of position won't make a lot of difference, however in the long term it will. A team in my League last season had 2 MCs as wingers for the entire season playing the same formation. The first 15 games he lost only once & drew twice. Then he lost 3 of the next five & lost his last 4 & missed a CL spot for this season. I feel sure the MCs playing OOP had something to do with his demise.

And I wouldn't quibble between a 72 quality player compared with a 75 quality player, the difference is negligible to say the least. Play the DCM in his normal role.